private const double arcs = 206264.806247; // Arcseconds per radian
// Start is called before the first frame update
void Start()
{
mat = GetComponent <Renderer>().material;
earth = GameObject.Find("Earth");
cam = GameObject.Find("Main Camera");
date = GameObject.Find("Date & Time");
iniScale = transform.localScale;
// Initialize Moon's rotation
EarthBehavior earthObj = earth.GetComponent("EarthBehavior") as EarthBehavior;
t = earthObj.GetT();
transform.Rotate(Vector3.up, -(float)(rotPerSec * t));
}
// Update is called once per frame
void Update()
{
// Get current speed multiplier from Date & Time
DateTimeDisplay dateObj = date.GetComponent("DateTimeDisplay") as DateTimeDisplay;
speed = dateObj.speed;
// Rotation about axis
transform.Rotate(Vector3.up, (float)(-rotPerSec * speed * Time.deltaTime));
// Get t from EarthBehavior
EarthBehavior earthObj = earth.GetComponent("EarthBehavior") as EarthBehavior;
t = earthObj.GetT();
T = tIni + t / secPerCent;
L_0 = Frac(0.606433 + 1336.851344 * T); // Mean longitude
l = 2 * Math.PI * Frac(0.374897 + 1325.552410 * T); // Moon's mean anomaly
lp = 2 * Math.PI * Frac(0.993133 + 99.997361 * T); // Sun's mean anomaly
D = 2 * Math.PI * Frac(0.827361 + 1236.853086 * T); // Diff. long. Moon-Sun
F = 2 * Math.PI * Frac(0.259086 + 1342.227825 * T); // Argument of latitude
// Compute Earth-Moon distance
r = 3.85 - 0.20905 * Math.Cos(l) - 0.03699 * Math.Cos(2 * D - l) - 0.02956 * Math.Cos(2 * D) - 0.0057 * Math.Cos(2 * l) + 0.00246 * Math.Cos(2 * l - 2 * D) - 0.00205 * Math.Cos(lp - 2 * D) - 0.00171 * Math.Cos(l + 2 * D) - 0.00152 * Math.Cos(l + lp - 2 * D);
CamBehavior camObj = cam.GetComponent("CamBehavior") as CamBehavior;
// Greatly exaggerate Earth-Moon distance if in top-down view
if (camObj.GetView() == 3)
{
r *= 100;
}
// Compute right ascension
dL = 22640 * Math.Sin(l) - 4586 * Math.Sin(l - 2 * D) + 2370 * Math.Sin(2 * D) + 769 * Math.Sin(2 * l) - 668 * Math.Sin(lp) - 412 * Math.Sin(2 * F) - 212 * Math.Sin(2 * l - 2 * D) - 206 * Math.Sin(l + lp - 2 * D) + 192 * Math.Sin(l + 2 * D)
- 165 * Math.Sin(lp - 2 * D) + 148 * Math.Sin(l - lp) - 125 * Math.Sin(D) - 110 * Math.Sin(l + lp) - 55 * Math.Sin(2 * F - 2 * D);
L = 2 * Math.PI * Frac(L_0 + dL / 1296000);
// Compute declination
S = F + (dL + 412 * Math.Sin(2 * F) + 541 * Math.Sin(lp)) / arcs;
h = F - 2 * D;
N = -526 * Math.Sin(h) + 44 * Math.Sin(l + h) - 31 * Math.Sin(h - l) - 25 * Math.Sin(F - 2 * l) - 23 * Math.Sin(lp + h) + 21 * Math.Sin(F - l) + 11 * Math.Sin(h - lp);
B = (18520 * Math.Sin(S) + N) / arcs;
// Compute (x,y,z) position of moon w.r.t. Earth
y = r * Math.Sin(B);
x = Math.Sqrt((Math.Pow(r, 2) - Math.Pow(y, 2))) * Math.Sin(L - 0.250434);
z = -Math.Sqrt((Math.Pow(r, 2) - Math.Pow(y, 2))) * Math.Cos(L - 0.250434);
earthDist = new Vector3((float)x, (float)y, (float)z);
earthPos = earthObj.GetPosition();
transform.position = earthPos + earthDist;
// Illuminate moon surface that's facing the sun
mat.SetVector("_LightDir", -transform.position.normalized / 2);
// Adjust scale based on view mode
if (camObj.GetView() == 3)
{
scaleFactor = 1000;
transform.localScale = scaleFactor * iniScale;
}
else if (camObj.GetView() == 0)
{
scaleFactor = 10;
transform.localScale = scaleFactor * iniScale;
}
else if (camObj.GetView() == 1)
{
transform.localScale = iniScale;
}
else
{
scaleFactor = 78;
transform.localScale = scaleFactor * iniScale;
}
}